1. Technical Field
The disclosure relates in general to a light-emitting device and a method for manufacturing the same, and more particularly to a light-emitting device with light-emitting element and a method for manufacturing the same.
2. Description of the Related Art
The organic light emitting diode (OLED), commonly used in the display and the illumination facility, can be divided into the fluorescent material system and the phosphorescent material system. The theoretical value of quantum effect of the fluorescent material system is about 25%, and theoretical value of quantum effect of the phosphorescent material system can be near 100%.
Despite the OLED can increase the internal quantum effect by adjusting element structures, most of the actually measured quantum effect of the element are smaller than 20%, which is indeed very low. The low quantum effect is mainly ascribed to the following reasons. First, the light emitted by the OLED is an isotropic light, which is emitted upwards, downwards, and laterally. Second, before reaching the display surface or the external, the light emitted by the OLED has to pass through or contact other structures of the device, and thus many of the lights are diffracted or deflected to unexpected paths. About 80% of the light generated by the OLED will be wasted in the device, not only deteriorating the optical performance of the light-emitting device but also wasting the generated light energy. This is indeed a waste of energy and by no means environmental friendly.